Some of the more than 130,000 fans who attended the first day of the 18th annual Electric Daisy Carnival at Las Vegas Motor Speedway on Saturday. (Credit: Los Angeles Times)

Coroner officials on Sunday morning were trying to determine what killed a 24-year-old California man, who died Saturday morning at a massive electronic music festival in Las Vegas.

Jennifer Jacobs, a senior investigator for the Clark County Coroner, said an autopsy was underway on the body of Montgomery Tsang. The results of the examination were expected Sunday afternoon, she said.

If the cause of death cannot be determined from the examination, toxicology tests will likely be required.